Laminated container seal with removal tab bound by adhesive

Abstract

A sealing member for a container comprises a heat actuated sealant or adhesive layer for securing the sealing member to a container, a metal foil layer over and covering and adhesively bonded to the heat actuated sealant or adhesive layer, and a polyethylene or polypropylene foam or film layer over and covering and adhesively bonded to the foil layer. In addition, a first PET tab defining layer lies over and covers at least a portion of, but is not adhesively bonded to at least part of that portion of, the polyethylene or polypropylene foam or film layer. Also a polypropylene film layer lies over and covers and is adhesively bonded to both the portion of the polyethylene or polypropylene foam or film layer not covered by the first PET tab defining layer and also to the first PET tab defining layer itself, the bonds being established by an adhesive resin and catalyst chosen to provide a high bonding strength sufficient to hold against a manually generated force. A second PET layer lies over and covers and adhesively bonds to the polypropylene film layer. The first PET tab defining layer and the portions of the propylene film and second PET layers immediately above and adhesively bonded to the first PET tab defining layer serve as a tab to facilitate removal of the sealing member from a container to which it has been adhered.

1 . A sealing member for a container comprising:
 a heat actuated sealant or adhesive layer means for securing the sealing member to a container;   a metal foil layer over and covering and adhesively bonded to the heat actuated sealant or adhesive layer means;   a polyethylene or polypropylene foam or film layer over and covering and adhesively bonded to the foil layer;   a first PET tab defining layer over and covering at least a portion of, but not adhesively bonded to at least part of that portion of, the polyethylene or polypropylene foam or film layer;   a polypropylene film layer over and covering and adhesively bonded to both the portion of the polyethylene or polypropylene foam or film layer not covered by the first PET tab defining layer and also to the first PET tab defining layer itself, the bonds being established by an adhesive resin and catalyst chosen to provide a high bonding strength sufficient to hold against a manually generated force; and   a second PET layer over and covering and adhesively bonded to the polypropylene film layer;   whereby the first PET tab defining layer and the portions of the propylene film and second PET layers immediately above and adhesively bonded to the first PET tab defining layer serve as a tab to facilitate removal of the sealing member from a container to which it has been adhered.   
     
     
         2 . A sealing member in accordance with  claim 1  wherein the polyethylene or polypropylene foam or film layer is polyethylene film. 
     
     
         3 . A sealing member in accordance with  claim 1  wherein the polyethylene or polypropylene foam or film layer is polyethylene foam. 
     
     
         4 . A sealing member in accordance with  claim 1  wherein the polypropylene film layer is a blown film in the range of 0.002 to 0.006 inches thick. 
     
     
         5 . A sealing member in accordance with  claim 1  wherein the polyethylene or polypropylene foam or film layer is 0.002 to 0.006 inches thick. 
     
     
         6 . A sealing member in accordance with  claim 1  wherein the polypropylene film layer and the polyethylene or polypropylene foam or film layer are more than twice the thickness of any of the PET layers. 
     
     
         7 . A sealing member in accordance with  claim 1  wherein a third PET layer lies between and is adhesively bonded to the heat activated sealant or adhesive layer and the metal foil layer to prevent corrosion of the metal foil layer. 
     
     
         8 . A sealing member for a container comprising:
 a hot melt bonding material or adhesive layer that, when heated, can secure the sealing member to the container, forming a seal to the container that can be broken through manual effort;   a sealing layer over and adhesively bonded to the hot melt bonding material or adhesive layer, the sealing layer comprising a metal foil layer;   a polyethylene or polypropylene foam or film layer, having a melting point near to or above 125 degrees Celsius and sufficiently thick to prevent heat from damaging the sealing member elements above this layer, is over and adhesively bonded to the foil layer;   a first PET tab defining layer over and covering at least a portion of, but not adhesively bonded to at least part of that portion of, the polyethylene or polypropylene foam or film layer;   a polypropylene film layer over and adhesively bonded to the portion of the polyethylene or polypropylene foam or film layer not covered by the first PET tab defining layer and also bonded to the first PET tab defining layer itself by an adhesive resin and catalyst having a bonding strength near to or above 3500 g/in; and   a second PET upper layer over and adhesively bonded to the polypropylene film layer;   whereby the first PET tab defining layer and the portions of the propylene film layer and the second PET upper layer immediately above and adhesively bonded to each other and to the first PET tab defining layer together form a removal tab that facilitates removal of the sealing member from a container to which it has been adhered by inductive heating.   
     
     
         9 . A sealing member in accordance with  claim 8  wherein the polyethylene or polypropylene foam or film layer is polyethylene film. 
     
     
         10 . A sealing member in accordance with  claim 8  wherein the polyethylene or polypropylene foam or film layer is polyethylene foam. 
     
     
         11 . A sealing member in accordance with  claim 8  wherein the polyethylene or polypropylene foam or film layer is polypropylene film. 
     
     
         12 . A sealing member in accordance with  claim 8  wherein the polyethylene or polypropylene foam or film layer is polypropylene foam. 
     
     
         13 . A sealing member in accordance with  claim 8  wherein the polyethylene or polypropylene foam or film layer is a co-extruded film comprised of both polyethylene and polypropylene. 
     
     
         14 . A sealing member in accordance with  claim 8  wherein the polyethylene or polypropylene foam or film layer is a blend comprising approximately 70% HDPE blended with MDPE. 
     
     
         15 . A sealing member in accordance with  claim 8  wherein the polyethylene or polypropylene film or foam layer is a blown film in the range of 0.002 to 0.006 inches thick. 
     
     
         16 . A sealing member in accordance with  claim 8  wherein the polyethylene or polypropylene film or foam layer is a foam layer in the range of 0.003 to 0.009 inches thick. 
     
     
         17 . A sealing member in accordance with  claim 8  wherein the polypropylene film layer is a polypropylene blown film in the range of 0.002 to 0.006 inches thick. 
     
     
         18 . A sealing member in accordance with  claim 8  wherein the polypropylene film layer is a co-extruded film comprising HDPE and polypropylene. 
     
     
         19 . A sealing member in accordance with  claim 8  wherein the adhesive resin and catalyst that bonds the polypropylene film layer to the portion of the polyethylene or polypropylene foam or film layer not covered by the first PET tab defining layer and also to the first PET tab defining layer has a bonding strength near to or above 4000 g/in. 
     
     
         20 . A sealing member in accordance with  claim 8  wherein the sealing layer further comprises an acid blocking PET layer inserted in between the metal foil layer and the hot melt bonding material or adhesive layer to prevent corrosion of the metal foil layer.